package trouger.dmt;

/**
 * An AggregationOperator object is associated to one particular column
 * of a table. all records from this table in a record group is aggregated by this 
 * operator, and one aggregated value is produced. 
 */
public interface AggregationOperator {
	/**
	 * Accept one column value from a record.
	 * @param value the column(field) value
	 */
	public void acceptValue(String value);
	/**
	 * Get the aggregated value.
	 * @return the aggregated value
	 */
	public String getAggregatedValue();
}
